MICROMECHANICS OF COUPLED ELECTROELASTIC COMPOSITES - EFFECTIVE THERMAL-EXPANSION AND PYROELECTRIC COEFFICIENTS

The effective thermal-expansion and pyroelectric coefficients of two-phase coupled electroelastic composite materials are obtained by coupling various micromechanics theories with exact relations connecting their effective thermal and electroelastic moduli. Results are obtained for composites reinforced by ellipsoidal piezoelectric inhomogeneities and thus are applicable to a wide range of microstructural geometry including lamina, spherical particle, and continuous fiber reinforcement. The analytical framework is developed in a matrix formulation in which the electroelastic moduli are conveniently represented by a 9 X 9 matrix and the thermal-expansion and pyroelectric coefficients by a 9 X 1 column vector. Numerical results are presented for some typical composite microstructures which show the interesting behavior of these materials.